Braga, who finished above Porto in the Portuguese league last season and knocked out Spain's Sevilla to reach the group stage of Europe's blue riband competition, were thrashed 6-0 by the rampant English team.
"We could not have played any worse," a shell-shocked Paciencia told reporters at the Emirates Stadium after an embarrassingly one-sided Group H opener.
NEWS:Arsenal batter Braga 6-0
"I wish we could have finished the game at half-time and even then it still would have been a bad experience.
"This was not the image we wanted to give of Braga. We've only lost three points but it was a night to forget."
Braga were picked apart by Arsenal skipper Cesc Fabregas who opened the scoring with a penalty and led the Portuguese defence a merry dance all night.
Arsenal were 3-0 up by half-time and but for some profligate finishing and the woodwork would have beaten their previous record home victory in Europe.
As it was Braga equalled their worst European defeat, suffered just down the road at Tottenham Hotspur in 1984.
Paciencia said he hoped his players would learn from the experience before taking on Shakhtar Donetsk and Partizan Belgrade.
"We can't play any worse than that," he said. "We know perfectly well we were playing against a top team and we'll have to use it as an experience. But let's not repeat it.
"We were just too nervous and gave them too much space."
